Apparatus for treating and storing meat



plfi 15,1947- P. B. CHRISTENSEN 2,419,139

APPARATUS FOR TREATING AND STORING MEAT 2 Sheets-Sheet 1 \9/ ATTORNEY w.. N+1 m Rr mm v NN WM d I N TBE 1v \|v m l www \y ww v uw R, \q u W J1 T. w m M v A kfw @WA w \mhl mi .\l\ l ww m UN {Whpu MQ April 15 1947- P. B. cHRxsTl-:NSEN 2,4`9fl A APPARATUS FOR TREATING AND STORING MEAT Original Filed Jan. 31, 1940 2 Sheets-Sheet 2 INVENTOR V R5. C# /JE/VS/V.

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ATTO R N EY Patented pr. 15, 1947 APPARATUS FOR TREATING AND STORING MEAT Paul B. Christensen, Fair Lawn, N. J., assignor, by

mesne assignments, to Westinghouse Electric Corporation, a corporation of Pennsylvania,

Continuation of application Serial No. 316,496, January 31, 1940. This application July 2, 1943,

Serial No. 493,227

8 Claims.

l This application is a continuation of my application led January 31, 1940, Serial No. 316,496, now forfeited and relates to the treatment of food, and more particularly to an improved 2 as about three days, while the growth of bacteria and mold is inhibited.

Other objects and advantages of the invention will become apparent as the description proceeds.

method and apparatus for tenderizing meat, fol- 5 In the James Patent #2,169,081 dated August lowing generally the teachings of the James Pat- 8, 1939, previously referred to, there is disclosed ent #2,169,081, dated August 8, 1939. and claimed a process for the treatment of meat The principal object of my invention, generally in order to tenderize the same at an increased considered, is to treat meat, vand especially beef, speed, while Iat the same time avoiding the deto improve the qualities thereof, with the special velopment of bacteria and mold on the surface of idea of avoiding the condensation of moisture on said meat when it is rst introduced cold to the tenderizing compartment, which normally contains humid air at a relatively high temperature.

An object of my invention is to provide a method for quickly tenderizing meat, in which the condensation of moisture on .the cold meat is avoided by temporarily automatically increasing the temperature and lowering the relative humidity of the surrounding air, to allow it to warm the newly introduced meat without depositing moisture thereon.

Another object of my invention is the provision of apparatus for treating meat, comprising Aa vcompartment containing means for circulating air, means for cooling and humidifying said `air, and means for temporarily heating the air, after humidication, but subsequent to they introduction of chilled meat into said compartment, until said meat has been warmed to a `desired tenderizing temperature, and thereby avoid condensation of moisture thereon.

A further object of my invention is the provision, in a meat tenderizing compartment, of lair-conditioning and circulating apparatus, in

cluding temperature control means for auto matically effecting a heating and lowering of lthe relative humidity of the circulating air upon a drop in temperature, as upon the introduction of chilled meat into said compartment, until said meat has been warmed to approximately the desired tenderizing temperature.

A still further object of my invention is lthe provision of humidifying, circulating and tem -perature maintaining apparatus in a meat treating compartment, whereby not only is lthe rate of flow of the circulated air controlled in accordance with the temperature in the compartment, but the relative humidity and temperature of said circulated air is varied in accordance with the temperature of .the meat subjected .to the tenderizing treatment.

An additional object of my invention is .to provide an improved process and apparatus for tenderizing meat in a relatively short time, such said meat. The process of said patent has proved very successful and the apparatus disclosed may be successfully employed for the purpose. However, when meat, in large pieces and/or on a large scale, is tenderized by a continuous process, that is when cold meat or that at a temperature between 35 and 40 F., is introduced at one place in a meat treating compartment, while meat, treated for a sufficient length of time to cause the desired tenderization thereof, is removed from another part of said compartment, there is a diiculty encountered in the rst step of the operation, due to the fact that it was necessary to move chilled meat, such as beef, whose exterior temperatures might be as low as 40, and interior temperature as low as 35, into a warm humid room for the actual tenderizing portion of the process. In accordance with physical laws, there would naturally occur the deposition of moisture on the surface of the beef by condensation. Such a situation is highly undesirable, as even thin lms of moisture will lead to a certain amount of loss of the natural bloom of the beef. In larger quantities, .this condensation will sometimes accumulate in drops and run down the beef, leaving unsightly streaks. Where drops accumulate but do not run, unsightly spots result. Any long exposure to heavy condensation, will produce eiects beyond discoloration, and lead ultimately to the development of undesirable odors on the fat of the beef, as well as accentuate and accelerate the activity of any organisms which might be present,A and which require moist conditions for their development.

Two means of attack were employed .to eliminate the above diiculties. In the rst place, the process was conducted as a batch operation, with a lot of beef being moved into the processing cooler maintained at a `temperature of F. desired for processing, but with no humidiication of the air in the cooler. Consequently, it was possible to warm the beef from its refrigerated temperature of 35-40 F. to the processing temperature of 60 F. without condensation occurring. This operation is objectionable because of shrinkage, meaning the evaporation of the moisture from the beef, would occur during the warming-up process, adding to the expense. In the second place, beef was moved into the processing cooler in a chilled condition, while the processing cooler was at a temperature of 60 F., and 85-90% relative humidity. As rapidly as condensation formed on the beef, it Was rubbed down for removal of this moisture. This operation was objectionable due to added labor costs, and because there was a certain small amount of deterioration in the fresh live appearance of the beef under these circumstances.

In accordance with my invention, it is necessary to have an air-conditioning unit for the recirculation of air in a cooler which will maintain a temperature of 60 F., requiring a cooling eiect at certain times, and a heating effect at other times. The operation is, of necessity, continuous and not of a batch nature as in previous work. The cooler is continuously maintained at 85-90%, or at about 90% relative humidity. Chilled beef being moved in, would be in the presence of other beef which had already been in the process for periods of one to two days. Naturally, condensation would occur on the new chilled beef being moved in. However, that, due to the operation of the air-conditioning unit, in accordance with my invention, does not occur to any appreciable extent, or to such an extent as to be of practical commercial importance. The effect of moving in a fresh load of chilled beef is to drop the temperature of the cooler several degrees, with the result that the automatic controls provided for maintaining the tenderizing rooms at 60 F. cause the heating apparatus to come into operation. Steam is admitted to the heating coil over which the cool air is circulated in the unit. The damper in the outlet from the unit to the ducts distributing air to the cooler, is opened to a wide position, so that there is a rapid recirculation f air through the cooler.

This operation causes high temperatures, in some cases as high as 80-90 F., to be temporarily delivered to the cooler. Humidication is accomplished by passing the circulating air through a water spray, at a temperature of 56 F., with the result that subsequent heating, as to 80-90 F., results in warm and relatively dry air being distributed to the cooler. The effect of such' warm dry air, is to first raise the temperature of the outside layers of the beef very rapidly from 35-40" F. to the temperature of the process room at 60 F., and then the rapid movement of said air serves to evaporate such very thin films of moisture, as might have already condensed on the beef. The result of this combination of operations is that cold meat, such as beef, can be moved into a warm humid room without condensation of undesired moisture, with all of its deteriorating eiects occurring. The operation is so adjusted that the period of time during which warm dry air is circulated over the beef is such that undesired condensation is entirely avoided, or eliminated Without damage, but not so long continued as to result in undue heating or appreciable shrinkage of the meat.

A record of these operations does not appear on the charts for dry bulb or wet bulb temperatures, since the control points or thermostat bulbs for these recording instruments are located in the inlet of the air-conditioning unit, and consequently measure the characteristics of the air after it has passed over the chilled beef and been cooled by such passage to a temperature of less than 60 F. Measurements of temperature establishing the fundamental conditions outlined above, were made with separate thermometers and instruments out in the cooler, and were not included as part of the operating charts for the process.

The apparatus required for the practicing of my invention may be mainly of standard commercial design and be used for many processes other than that outlined above. A typical unit for the air-conditioning causesV air to pass through a spray of chilled water, which is recirculated within the unit itself. This spray water is cooled by coils through which are circulated a refrigerant. In some cases it is advisable and desirable to have the spray water chilled in a remote type water cooler in which these coils are f located, but generally it is satisfactory to havev the spray water cooling coil located within the casing of the air-conditioning unit. The temperature of the spray may be controlled by a thermostat located in the spray or reservoir of spray water, and operating control valves on the refrigerant lines to the cooling coil.

After passing through the spray, the air passes over coils to which steam may be admitted for heating the air when desired, and controlled by a thermostat bulb located either at the end of the cooler, or out in the cooler itself. with this heating operation, a motor-operated damper in the outlet duct from the unit, is opened as heating is required so that a high rate of air circulation is maintained during the period in which the temperature is being raised back to 60 F., after chilled meat has been introduced.

When the need for heat is past, the steam is cut off from the coils and the damper controlling the heating, comes back to a nearly closed position, thus cutting down the flow of air to a small value. In actual practice, it has been found that even a very heavy loading of chilled beef in the processing cooler, will require a period varying from a few minutes to one to two hours, depending on the temperature of the beef. Consequently there is avoided for the greater part of the forty-eight to seventy-two hour period, which the beef must spend in the processing cooler, a rapid passage of warm air of relatively low humidity, which is accompanied by shrinkage.

Beef, as received in the cooler, will be at a variety of temperatures. When moved from a packers cooler in the same town-with a relatively short truck trip, temperatures are apt to be in the 35 to 40 F. range. When brought from a considerable distance by truck, the temperatures will be more nearly that of the processing room, and may be as high as 50 F., when received. The danger of condensation is very slight in the latter case.

In the drawings:

Figure 1 is a Vertical sectional View of a refrigerator, or meat treating compartment, embodying and including means for practicing my invention.

Figure 2 is a transverse, sectional View on the line II-II of Figure 1 in the direction of the arrows.

Figure 3 is an enlarged detailed sectional view of the means for controlling the circulation of air in the compartment of the preceding figures, and

Figure 4 is a fragmentary portion of a diagram illustrating what takes place when refrigerated or chilled meat is rst introduced into a meat In connection tenderizing compartment in accordance with my invention.

Referring to the drawings in detail, and rst considering Figures 1, 2 and 3, there is shown a fragmentary portion of a commercial meat tenderizing compartment or cooler II, provided with rails l2, on which meat carriages I3 travel, said carriages I3 being desirably provided with hooks or other meat-holding means I4, from which depend carcasses or pieces of meat or beef I5. The compartment I I may be entered through a vestibule or anteroom (not shown) having a door leading to the outside, or any suitable means for entrance and egress may be provided.

Instead of providing refrigerating coils directly in the meat-treating compartment, as shown in the James patent previously referred to, I have shown the employment of a spray type air conditioning unit in a chamber I6, the operation of which is controlled by instruments I1 and I8. The desired temperature of above 45 F., or about 60 F., in the compartment II is maintained by circulating air from the room through the unit I6, as by means of fan or blower I9, The air enters unit I6 through inlet 2l, passes upward through water spray 22, in which it is cooled to the desired temperature, preferably about 56 F., or about 4 degrees lower than the desired temperature of the air in said compartment at the same time being saturated to approximately 95% relative humidity by said spray, and passes again into the compartment II through duct system 23.

The water which forms the spray 22 is forced from reservoir of spray water 24, as by means of pump 25 driven by motor 25, through pipe 21, and is maintained at a desired constant temperature of about 56 F., as by cooling coil 28 through which ows cold brine, circulated as by means of pump 29. The temperature of the water 24, and consequently that of the spray 22, is regulated by instrument i8, which is actuated by temperature-sensitive bulb 3l located in the reservoir of spray water 24. The instrument I8, in turn, actuates the three-way mixing valve 32, as by means of compressed air from air pressure supply tank lines 33, to branch line 34. The air in the line 34 acts on the diaphragm 35, When desired, and moves the valve lever 36 to introduce more or less of the cold brine from the supply pipe 31 to the circulating pipe 38, which connects with the cooling coil 28, whereby the temperature of said cooling coil corresponds with the needed temperature of the spray water for maintaining a desired tenderizing temperature of about 60 F. in the compartment II.

They operation of the instrument I8 is such that when the spray water in the reservoir 24 is at the desired temperature, no compressed air is admitted to the pipe 34, so that the valve 32 is closed entirely against brine from the cold supply through pipe 31 and open entirely for recirculating in the line 38. When, however, the temperature of the Water in the reservoir 24 is too high, compressed air is allowed to iiow through pipe 34 to act on the diaphragm 35 and turn the lever 35 of the valve 32, allowing more or less of the cold brine from the supply through pipe 31 to flow into the system through pipe 38 until the brine circulated by the pump 29 is at the desired temperature. An amount of brine, equal to that introduced by the three-way valve 32, ows back to the cold brine supply through the return pipe 39.

By thus maintaining the Water spray 22 at a constant temperature of desirably 4 less than that of the air in the compartment, or say at 56 F., the dew point of the air leaving the unit through duct system 23 is maintained constant. This is dependent on having a suicient quantity of spray 22 to saturate the air to about when the unit is circulating the maximum quantity of air.

The dry bulb temperature of the chamber is controlled by the instrument I1, which has its temperature sensitive element 4I located in the air inlet 2l to the air conditioning unit I6. Instrument I1 may be a standard pneumatic type temperature controller which operates a standard pneumatically operated steam valve 42, and a standard pneumatically operated damper motor 43. Damper motor 43 operates a full floating damper 44, as shown most clearly in Figure 3, as by means of diaphragm 45, connecting rod 45, lever 41 pivoted to bracket 48, as indicated at 49, and link 5I pivoted to the free end of lever 41 and to damper 44.

When air passing over the bulb 4I is at a desired control temperature of say 60 F., the bulb 4I controls the instrument I1 so that it allows a certain denite air pressure, say 71/2 pounds, to be supplied to branch line 52 from the main air supply 33, in which the pressure is desirably from l5 to 17 pounds. With this 71/2 pound gauge pressure in line 52, steam valve 42 is so adjusted as to be in a closed position, and damper motor 43 is so adjusted as to hold the lever 41 in the neutral position indicated by the reference character 41a, which, in turn, holds damper 44 in its closed position, indicated by the reference character 44a.

When the refrigeration load in the compartment II is at a minimum, that is, when meat to be tenderized has reached normal tenderizing temperature, the damper 44 is in position 44a and the auxiliary damper 53 is then set by hand to such a position as t0 allow just suicient air to pass from unit IS through duct system 23 into the compartment II, to maintain the desired temperature therein. If the temperature of the air passing over bulb 4I increases, said bulbI actuates instrument I1 in such a manner as to allow the pressure of the air in the line 52 to increase. This actuates damper motor 43 to move lever 41 from position 41a toward position 41h, and damper 44 from position 44a to position 441), thus allowing more air to pass into duct system 23, and from there back into the compartment II, to reduce the temperature therein, while keeping steam valve 42 closed.

If the temperature of the air passing over bulb 4I is then lowered to the control point, that is, to 60 F. for example, lthe entire mechanism will return toits original position, with the damper as indicated by the reference character 44a. If the temperature of the air passing over bulb 4I falls below the control point, as when a new supply of refrigerated or chilled beef is introduced into the compartment II, the bulb 4I actuates instrument I1 in such a manner as to decrease the air pressure in branch line 52 below 'Z1/2 pounds, as the air passes through the instrument from supply line 33. This reduction in air pressure allows the diaphragm 54 of the steam valve controlling motor 55 to move up- Wardly under the action of spring 56 and open the valve 42, admitting steam to the heating coil 51. At the same time, the reduction of air pressure in line 52 actuates damper motor 43, moving lever 41 from its position 41%L back toward its full line position, which, in turn, moves damper 44 from its position 44a toward its full line position.

This combination of actions reheats the air after it passes through spray 22 and baffles 58, Which latter remove water drops therefrom, and allows an increased quantity of this air, heated so that its relative humidity decreases, to pass into duct 23, and then into the compartment Il, to increase the temperature of the air therein. As the temperature in said compartment is brought to a point at which the air passing over bulb 4| is returned to the control point, say 60 F., the entire mechanism again returns to its original position at said point.

Referring now to Figure 4, there is disclosed a portion of a chart made on a recording instru- (ment which shows what happens ywhen a batch of cold beef, or other mea-t, is brought into said compartment. The upper or outer line 59 of said chart represents the temperature of the air around the meat in the compartment as would be measured by lil, while the lower or inner line 6| represents the temperature of the spray 22, as measured by 3l. It will, therefore be clear, that the rst dip in both lines, at about 8:20 a. m., represents what happens when a batch of chilled meat is rst introduced into the compartment Il. That is, the line 59 dips from about 60 F. to about 55 F. causing the valve 62 to open and admit steam to the heating coil 51, and also opening the damper fill by moving it toward its full-line position and causing an increased circulation of air through the duct system 23, resulting, after irregularity, eventually in an abnormal rise in the compartment temperature, to, in this instance about 63 F., at about 8:45 a. m., after which said temperature gradually decreases to normal.

It will thus be seen that by virtue of the temporary increase in temperature, and corresponding reduction in humidity, after a batch of cold meat has been introduced into the compartment, said increased temperature and relative dryness serves to more quickly bring the chilled meat to a normal tenderizing temperature and, at the same time, avoids a condensation of any appreciable or undesirable amount of moisture on said meat during the warming-up period.

Inasmuch as the present invention involves an improvement over that disclosed in the James patent, previously referred to, and the primary object is to make it possible to tenderize lbeef and other meat in a shorter time than in accordance with the old hanging method, it is essential than an inhibitor of aerobic growths shall be used as disclosed in connection with said patent. In other words, at the substantial increase in temperature at which meat is held for tenderizing purposes, it is not possible without such means to prevent rapid aerobic growths, and I, therefore, propose to use inhibiting means to prevent spoilage due to surface deterioration from such aerobic growths which are either present on the meat as received in the compartment, or may be deposited thereon from the air therein.

radiant energy lamps operated at low temperature and generating ultra-violet radiations which will kill bacterial, fungus, and other aerobic organisms, before they have a deteriorating eifect on the surface of the meat. I prefer to use a lamp such as described and claimed in the James Patent No. 2,258,765, because such a lamp generates rays in which the spectrum in the region between 2500 and 3000 A. U. is strong, with subs Preferred surface growth inhibiting means are" stantially no radiations below about 2500 A. U. and in the infra-red region. The intensity of the radiations from such lamps may be regulated by the current therethrough so that those generated are suiiicient to inhibit the growth of fungi and bacteria, without causing rancidity of the fat or other undesirable effects within the period of time required for tenderizing the meat.

In Figures 1 and 2, I have indicated the disposition of such lamps by the reference character B2, for those which are longitudinally disposed with respect to the compartment Il and lie intermediate the side walls thereof. Other lamps of the same character.; designated as 63, may be disposed along the walls, as indicated, and all are desirably positioned above the meat and provided with reflectors 64, so as to direct the radiations therefrom downwardly upon the meat for exerting a bactericidal action thereon.

A preferred disposition of the lamps is such that they are not directly in the path of the strongest air currents whereby they operate more efficiently. In other words, some ofKA said lamps are disposed directly beneath the branches of the air duct system 23, while others are disposed at about the same level, but lie along the side walls, and all of said lamps are protected from strong air currents, not only because of their positions, but also by the overlying reflectors 64.

From the foregoing disclosure, it will be seen that I have provided improved means for not only tenderizing meat, but also for avoiding undesirable moisture condensation on said meat when first introduced in a chilled condition to the warmer and more humid tenderizing compartment, by temporary decrease in the relative humidity of the circulating air, at the same time increasing the efficiency of tenderizing by bringing the meat up to the desired tenderizing temperature in a more expeditious manner than would be possible if the air in the compartment were not temporarily increased in temperature.

Although a preferred embodiment of my invention has been disclosed, it will be understood that modifications may be made within the spirit and scope of the appended claims.

I claim:

l. In apparatus for treating and/or storing meat, the combination of a compartment having air distributing ducts, a normally closed damper for controlling the flow of air to said ducts, air conditioning means disposed in said compartment and comprising a chamber connected to said ducts and having a reservoir of water disposed in the bottom thereof, a blower in the top thereof for circulating air from said compartment through said chamber o-ver said water and distributing it to said compartment through said ducts, spray nozzles disposed between said water and blower, means for drawing water from said reservoir and discharging it through said nozzles to humidify the circulating air and return tosaid reservoir, means in said compartment for controlling the temperature of said water, temperature sensitive means immersed in said water to govern the action of said controlling means, a cooling coil in the path of the spray from said nozzles, said controlling means causing circulation of more or less cooling fluid through said cooling coil to keep the reservoir water at substantially uniform temperature in accordance with the action of said sensitive means, a heating coil disposed between said nozzles and blower, a temperature controller disposed in said compartment, and sensitive means in the inlet to said chamber for causing said temperature controller to eect the admission of heating iluid to said heating coil, when the temperature of the air in said inlet is reduced below a predetermined point, and simultaneously open said damper to allow increased circulation through said ducts to bring the temperature in the -compartment back to normal.

2. In apparatus for treating and/or 'storing meat, the combination of a compartment having air distributing ducts, a normally closed damper for controlling the ow of air to said ducts, air conditioning means comprising a chamber connected to said ducts and having a reservoir of water disposed in the bottom thereof, a blower in the top thereof for circulating air from Said compartment through said chamber over said water and distributing it to said compartment through said ducts, spray no-zzles disposed between said water and blower, means for drawing water from said reservoir and discharging it through said nozzles to humidify the circulating air and return to said reservoir, means in said compartment for controlling the temperature of said water, temperature sensitive means immersed in said water to govern the action of said controlling means, said controlling means causing circulation of more or less cooling uid through means to keep the reservoir water at substantially uniform temperature in accordance with the action of said sensitive means, a heating coil disposed between said nozzles and blower, a temperature controller disposed in said compartment, and sensitive means in the inlet to said chamber for causing said temperature controller to effect the admission of heating fluid to said heating coil, when the temperature of the air in said inlet is reduced below a predetermined point, and simultaneously open said damper to allow increased circulation through said ducts to bring the temperature in the compartment back to normal.

3. In apparatus for treating and/or storing meat, the combination of a compartment having air distributing ducts, a normally closed damper for controlling the flow of air to said ducts, air conditioning means disposed in said compartment and comprising' a chamber connected to said ducts and having a reservoir of water disposed in the botte-m thereof, means for circulating air from said compartment through said chamber over said water and distributing it to said compartment through said ducts, means for drawing water from said reservoir and spraying to humidity the circulating air, means in said compartment for controlling the temperature of said water, temperature sensitive means immersed in 'said water to govern the action of said controlling means, said controlling means causing circulation of more or less cooling iluid through means to keep the reservoir water at substantially uniform temperature in accordance with the action of said sensitive means, heating means disposed between the spraying means and blower, a temperature controller disposed in said compartment, and sensitive means in the inlet to said chamber for causing said temperature controller to energize said heating means when the temperature of the air in said inlet is reduced below a predetermined point, and simultaneously open said damper to allow increased circulation through said ducts to bring the temperature in the compartment back to normal.

4i. In apparatus for treating and/or storing meat, the combination of a compartment having air distributing ducts, a normally closed damper for controlling the low of air to said ducts, air conditioning means comprising a chamber connected to said ducts and having a reservoir of water disposed in the bottom thereof, a blower in the top thereof for circulating air from said compartment through said chamber over said water and distributing it to said compartment through said ducts, spray nozzles disposed between said water and blower, means for drawing water from said reservoir and discharging it through Isaid nozzles to humidify the circulating air, means in said compartment for controlling the temperature of said water, temperature sensitive means immersed in said water to govern the action of said controlling means, said controlling means causing circulation of more or less cooling fluid through means to keep the reservoir water at substantially uniform temperature in accordance with the action of said sensitive means, a heating coil disposed between said nozzles and blower, a temperature controller disposed in said compartment, and sensitive means in the inlet to said chamber for causingr said temperature controller to effect the admission of heating fluid to said heating coil, when the temperature of the air in said inlet is reduced below a predetermined point, and simultaneously open said damper to allow increased circulation through said ducts to bring the temperature in the compartment back to normal.

5. In apparatus for treating and/or storing meat, the combination of a compartment having air distributing ducts, a normally closed damper for controlling the ow of air to said ducts, air conditioning means disposed in said compartment and comprising a chamber connected to said ducts and having a reservoir of water disposed in the bottom thereof, a blower in the top thereof for circulating air from said compartment through said chamber over said water and distributing it to said compartment through said ducts, spray no-zzles disposed between said water and blower, means for drawing water from said reservoir and discharging it through said nozzles to humidity the circulating air and return to said reservoir, means in said compartment for controlling the temperature of Said water, temperature sensitive means immersed in said water to govern the action of said controlling means, said controlling means causing circulation of more or less cooling fluid through means to keep the reservoir water at substantially uniform temperature in accordance with the action of said sensitive means, a heating coil disposed between said nozzles and blower, a temperature controller disposed in said compartment, and sensitive means in the inlet to said chamber for causing said temperature controller to effect the admission of heating iluid to said heating coil, when the temperature of the air in said inlet is reduced below a predetermined point, and simultaneously open said damper to allow increased circulation through said ducts to bring the temperature in the compartment back to normal.

6. In apparatus for treating and/or storing meat, the combination of a compartment having air distributing ducts, a normally closed damper for controlling the flow of air to said ducts, air conditioning means for said compartment and comprising a chamber connected to said ducts and having a reservoir of water disposed in the bottom thereof, a blower in the top thereof for circulating air from said compartment through said chamber over said water and distributing it to said compartment through said ducts, spray nozzles disposed between said water and blower, means for drawing water from said reservoir and discharging it through said nozzles to humidify the circulating air and return to said reservoir, means in said compartment for controlling the temperature of said water, temperature sensitive means immersed in said water to govern the action of said controlling means, cooling means for the Water to be sprayed from said nozzles, said controlling means causing more or less action of said cooling means to keep the reservoir water at substantially uniform ternperature in accordance with the action of said sensitive means, a heating coil disposed between said nozzles and blower, a temperature controller disposed in said compartment, and sensitive means in the inlet to said chamber for causing said temperature controller to eiTect the admission of heating fluid to said heating coil, when the temperature of the air in said inlet is reduced belowva predetermined point, and simultaneously open said damper to allow increased circulation through said ducts to bring the temperature in the compartment back to normal.

7. In apparatus for treating and/or storing meat, the combination of a compartment having air distributing ducts, a normally closed damper for controlling the iiow of air to said ducts, air conditioning means comprising a chamber connected to said ducts and having a reservoir of water disposed in the bottom thereof, a blower in the top thereof for circulating air from said compartment through said chamber over said water and distributing it to said compartment through said ducts, spray nozzles disposed between said Water and blower, means for drawing water from said reservoir and discharging it through said nozzles to humidify the circulating air and return to said reservoir; means in said compartment for controlling the temperature of said water, temperature sensitive means immersed in said water to govern the action of said controlling means, said controlling means causing circulation of more or less cooling uid through means to keep the reservoir water at substantially uniform temperature in accordance with the action of said sensitive means, a heating coil disposed between said nozzles and blower, a temperature controller disposed in said compartment, and sensitive means in the inletto said chamber for causing said temperature controller to open said damper, to allow increased circulation through said ducts to bring the temperature in the compartment back to normal, in one direction when the temperature of the air in said inlet is reduced below, and in the other direction when said temperature is increased above, a predetermined point, and simultaneously eect the admission of heating fluid to said heating coil only when the temperature of the air in said inlet is reduced below a predetermined point.

8. In apparatus for treating and/or storing meat, the combination of a compartment, a blower for circulating air in said compartment, control apparatus including al reservoir of water, means of controlling the temperature thereof, spray nozzles disposed in the path of said circulated air, means for drawing water` from said reservoir and discharging it through said nozzles for maintaining desired temperatures and humid'ities in said air, a heating coil disposed between said nozzles and blower, an air temperature controller disposed in said compartment, and sensitive means for causing said temperature controller to ei'ect the admission of heating uid to said coil when the temperature of air circulating thereover is reduced below a predetermined point, and simultaneously increase the circulation of air from said blower, as when meat which chills said air below the dew pointis introduced, until said meat has been increased in temperature suciently to avoid condensation of moisture thereon.

PAUL B. CHRIS'I'ENSEN.

REFERENCE S CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,068,272 Rayson July 22, 1913 2,169,081 James Aug. 8, 1939 1,861,158 Hilger May 31, 1932 2,207,714 Bulkeley July 16, 1940 2,250,260 Fowler July 22, 1941 OTHER REFERENCES The Tenderization of Meat, published 'by the Industrial Fellowship on Meat Merchandising, Mellon Institute, Pittsburgh, Pa., 1940, pages 1 to 6. 

